1. Field of the Invention
The present invention relates generally to an electronic door locking system for an automotive vehicle, and more specifically to an anti-theft automatic doorlocking apparatus used with an electronic vehicle-door locking/unlocking system.
2. Description of the Prior Art
The background of the present invention will be explained with respect to its application to the system used with an automotive vehicle.
As is well-known, there exists an electronic push-button type door locking system for an automotive vehicle, by which vehicle doors can be locked or unlocked when the driver depresses a plurality of push-button type switches installed at an appropriate position on the outside of an automotive vehicle in accordance with a predetermined code. When such an electronic vehicle door locking system as described above is used to lock or unlock the doors, since the vehicle doors can be locked or unlocked by the driver without the ignition key, it is very convenient for the driver, in particular, when the vehicle is left parked.
In the above-mentioned electronic door locking system, however, since the vehicle doors can be locked from the outside of the vehicle without use of the ignition key, when the driver parks his vehicle, there exists a problem in that he might leave his vehicle without locking the doors by using the electronic push-button type door locking system and, what is worse, with the ignition key left inserted in the ignition keyhole.
In the case where the vehicle is left parked in the driver's own private parking space with the ignition key left in the ignition keyhole, there may be little chance of the vehicle's being stolen; however, in the case where the vehicle is left parked in public out of the driver's sight with the ignition key left in the ignition keyhole, since a thief can readily see whether or not the ignition key is left inserted in the ignition keyhole, there may be a chance that the thief can easily steal the vehicle by using the ignition key left in the keyhole.